hey guys i don't know much about railers etc. but my 99 suburban doesn't have a hitch. i want to start trailering my motorcycle on this platform that hangs on the hitch. i don't know if anyone has seen them but it probably weighs over 100lbs plus my bike weighs another 600-700lbs. i looked at a class 3 and i don't know what tongue weight is and all that stuff can someone explain please?